Materials Literature
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Charge transfer and recombination at the single crystalline ZnO photoanode were studied by a combination of dc and ac techniques. The potential dependence of the spectrally resolved photoluminescence gives information on the competition between bulk recombination and electron−hole pair separation. The kinetics of surf…
New methodology was developed for synthesis of regiochemically pure porphyrins with D 2 h symmetry (e.g. 9 ) via tetramerization reactions involving two different pyrroles. The two pyrrole components were a 2,5-diunsubstituted pyrrole (e.g. 11 ) and a 2,5-bis[( N,N- dimethylamino)methyl]pyrrole (e.g. 10 ), the latter…
(meso-Tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphinato)manganese(III) tetracyanoethenide, [MnTP'P][TCNE], has been structurally and magnetically characterized. [MnTP'P][TCNE] (C(96)H(108)MnN(8)O(4)) belongs to the triclinicP&onemacr; (No. 2) space group with a = 8.597(2) Å, b = 14.756(4) Å, c = 17.573(5) Å, alpha…
Nine polyesters were synthesized by polycondensation of silylated hydroquinone with substituted terephthaloyl chlorides. Three mono(alkylthio), three bis(alkylthio), and three tetra(alkylthio)terephthaloyl chlorides were used as reaction partners. The length of the alkyl side chains was varied among 8, 12, and 16 carb…
Cellular films may be produced through evaporation of aqueous dispersions containing polymeric particles. The membranes of the cells are made of hydrophilic polymers which cover the particle surfaces; they form a periodic structure which separates the hydrophobic particle cores. These films are used to make adhesive c…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTOn Spherulitic Growth in a Monodisperse ParaffinD. C. Bassett, R. H. Olley, S. J. Sutton, and A. S. VaughanView Author Information J. J. Thomson Physical Laboratory, University of Reading, Reading RG6 6AF, U.K.Cite this: Macromolecu…
Dry-roasted peanuts were coated with whey protein isolate (WPI)/glycerol solutions. Accelerated rancidity tests of uncoated and coated nuts were performed. Coating thickness and environmental relative humidity were studied as factors that affected rancidity. In addition, the effect of limiting the amount of WPI soluti…
Mixed-valence states of μ-oxo-centered trinuclear iron carboxylate complexes, [Fe 3 O(CH 2 BrCO 2 ) 6 (H 2 O) 3 ] ( 1 ), [Fe 3 O(CH 3 CO 2 ) 6 (H 2 O) 3 ]·2H 2 O ( 2 ), and [Fe 3 O(CH 2 ClCO 2 ) 6 (H 2 O) 3 ]·3H 2 O ( 3 ), were characterized by X-ray crystallography and 57 Fe-Mössbauer spectroscopy. Compound 1 has a t…
(2-Nitro-5,10,15,20-tetraphenylporphyrinato)nickel(II) reacts with α-isocyanoacetic esters in the presence of DBU to give the first β-fused pyrroloporphyrins, the pyrrole ring in the fused system being shown to undergo typical pyrrole-type chemistry; the corresponding zinc(II) complex affords a novel cyclopropanochlor…
Cs, Ag, and Zn behave in a different way when deposited on surfaces of ultrathin (15−20 Å) films of alumina. In the case of Cs/Al 2 O 3, the alkali atoms wet the oxide, forming strong chemisorption bonds. At small coverages of Cs, desorption of the alkali occurred between 600 and 1000 K. As the amount of Cs deposited…
A technique is introduced for the theoretical prediction of electronic spectra of lanthanide complexes by replacing the metal ion by a point charge with the ligands held in their positions as determined by the SMLC/AM1, and by computing the theoretical spectra via the intermediate neglect of differential overlap/spect…
In a former paper, the dimensional properties of degraded starch fractions of different molar masses were reported. The behavior was found to be dominated by the highly branched amylopectin. The same samples are now investigated in semidilute solution by static−dynamic light scattering. The deviating values of the ove…
In 1887, Kelvin posed one of the most discussed scientific questions of the last 100 years - the problem of the division of three-dimensional space into cells of equal volume with minimal area. It has interested mathematicians, physical scientists and biologists ever since and the problem has scientific relevance to f…
A series of lead zinc phosphate glasses containing 30-80 mol% P 2 O 5 , 0-60%PbO and 0-60%ZnO have been prepared and characterised. The composition dependence of density, melting temperature(T m ), vitrification range, thermal behaviours (thermal expansion coefficient, glass transformation temperature, Tg and softenin…
This paper describes the results of investigation into the influence of a kind of nonsoluble contaminant (Tonoko or Kaolin) on flashover voltages of artificially contaminated insulators. The deposit density of Kaolin on the insulator surface is less than that of Tonoko when contaminated with the suspension containing…
Vapor deposition of a 45-Å layer of silver and a subsequent 50−65-Å layer of SiO 2 onto a glass slide is shown to be a viable substrate for surface-enhanced Raman spectroscopy (SERS) and a model of the silica surface suitable for adsorption kinetic studies. The chemistry of the silica is characterized by UV absorption…
The NMR spectra of polyamide 46/polyamide 6I copolymers, which were obtained by reaction in the molten sate, are studied. Using 13 C NMR, a physical blend of polyamide 46 and polyamide 6I and a polyamide 46/polyamide 6I copolymer could be discriminated. Four kinds of diad sequences are observed in the carbonyl resonan…
The adsorption of different ethoxysilanes on Al was studied. It was established that during polymolecular adsorption of ethoxysilanes from the vapor phase on aluminum the first monolayer is adsorbed irreversibly with adsorption van der Waals bonds between silane molecules and the aluminum surface. The covalent bonding…
Chain-folded single crystals of the five even−even nylons 4 4, 6 4, 8 4, 10 4, and 12 4 were grown from solution and their structures and morphologies studied using transmission electron microscopy, both imaging and diffraction. Sedimented mats were examined using X-ray diffraction. All these nylons have room temperat…
In catalysis, it has been suggested that the addition of CeO2 and other rare-earth metal oxides to alumina can stabilize the surface area and the spinel transition phases of the alumina support used in automotive catalysis. As this structural stabilizing effect by CeO2 was recently observed to occur only to a very lim…